Two-photon absorption and self-phase modulation measurements with shaped femtosecond laser pulses

We show that phase-sensitive detection of spectral hole refilling can yield information about self-phase modulation and two-photon absorption coefficients. We expect that, when applied to tissue microscopy, this technique will allow the study of endogenous molecular markers beneath the surface, even if those markers are nonfluorescent. (c) 2005 Optical Society of America.